[Ocular manifestations in mitochondrial DNA abnormalities].

We reviewed the ophthalmological and genetic aspects of mitochondrial diseases, a group of multisystem disorders that involve the function and morphology of mitochondria and affect multiple organs including skeletal muscle, central nervous system, heart, and ear. Disease-specific deletion or point mutation of mitochondrial DNA (mtDNA) has been clarified in many clinical entities of the group, and we confirmed that the ocular manifestations, including chronic progressive external ophthalmoplegia, blepharoptosis, retinochoroidal degeneration and optic nerve atrophy, develop in association with either deletion or point mutation of mtDNA. Together with a review of the literature, we describe a case of myoclonic epilepsy and ragged-red fibers with mutation at mtDNA 8344 and insidious bilateral optic atrophy. We also describe cases of myotonic dystrophy which had an abnormal expansion of CTG repeat of chromosome 19 protein kinase gene and showed retinochoroidal degeneration and mitochondrial morphological changes.